JSON diff

Find what changed between two JSON documents

JSON is everywhere: API responses, configuration files, exported data, package manifests. Sooner or later you need to know what differs between two versions of one: a response before and after a change, the config of two environments or a file that a colleague edited. A normal text comparison is a poor fit because JSON can be formatted in many ways, and the same content can appear with different spacing or with the keys in another order. This tool compares the data, not the text.

How the comparison works

Both documents are parsed and their structures are compared, walking through every object and list. For each difference you get the path in a form such as $.address.city or $.tags[1], and its kind:

• Added: a key or item that exists only in the new document.
• Removed: a key or item that exists only in the original.
• Changed: the same place holds a different value, shown as old value and new value. If the type changed, for instance from a number to a string, it is flagged too.

What is ignored and what is not

The order of the keys in an object never matters, because in JSON an object is an unordered set of pairs. Spacing and line breaks are ignored, and the numbers 1 and 1.0 are treated as equal. For lists you choose: by default items are compared by position, so inserting an item at the start shifts everything after it. If the order of the items is not meaningful, choose to ignore it and the tool matches equal items wherever they are.

Errors in the JSON

If one of the documents is not valid JSON, the tool says which one, and shows the line and column of the problem so you can fix it, with an explanation such as a missing comma or an unclosed quote.

Limits

It shows up to 500 differences. Very large numbers are compared by their written value, so they are not rounded. It does not merge the two documents or produce a patch. Both texts stay in your browser. To tidy a document before comparing it, use the JSON formatter.